The Mont-Blanc exploded in a fraction of a second.
The most immediate and devastating effect of the explosion was a shockwave produced by the detonation that was the equivalent of 2989 tons of TNT. The shockwave travelled at a speed of more than 1500 meters per second.
At the center of the blast the heat produced by the chemical reaction was in excess of 5000C. The heat and pressure pushed a fireball of hot gases, and debris consisting of soot, unburned coal, carbon from explosives, and shrapnel high into the sky above the harbour. As the gases cooled a giant cloud formed, the soot, carbon, and shrapnel fell as a deadly shower.
Around the Mont-Blanc the water was vaporized by the heat, the pressure of the explosion sent a 16 meter tidal wave out into the harbour and up into the Richmond neighbourhood for three city blocks.
